From 6b267a7367789ffa970c40988c638ffc8ade2c4f Mon Sep 17 00:00:00 2001
From: Tarek Sherif <tsherif@gmail.com>
Date: Tue, 15 Mar 2016 18:54:24 -0400
Subject: [PATCH] Alpha premultiplied in FS for proper compositing.

---
 src/core/display/chunks/flagsChunk.js        | 2 +-
 src/core/display/chunks/regionMapChunk.js    | 2 +-
 src/core/display/chunks/renderTargetChunk.js | 2 +-
 src/core/display/programSourceFactory.js     | 4 ++++
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/core/display/chunks/flagsChunk.js b/src/core/display/chunks/flagsChunk.js
index 0f32565c..924828a6 100644
--- a/src/core/display/chunks/flagsChunk.js
+++ b/src/core/display/chunks/flagsChunk.js
@@ -63,7 +63,7 @@ SceneJS_ChunkFactory.createChunkType({
                     // Entering a transparency bin
 
                     gl.enable(gl.BLEND);
-                    gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
+                    gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
                     frameCtx.blendEnabled = true;
 
                 } else {
diff --git a/src/core/display/chunks/regionMapChunk.js b/src/core/display/chunks/regionMapChunk.js
index 750bbf15..bf19ae8e 100644
--- a/src/core/display/chunks/regionMapChunk.js
+++ b/src/core/display/chunks/regionMapChunk.js
@@ -30,7 +30,7 @@ SceneJS_ChunkFactory.createChunkType({
                 // Entering a transparency bin
 
                 gl.enable(gl.BLEND);
-                gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
+                gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
                 frameCtx.blendEnabled = true;
 
             } else {
diff --git a/src/core/display/chunks/renderTargetChunk.js b/src/core/display/chunks/renderTargetChunk.js
index f940c03e..4f146c48 100644
--- a/src/core/display/chunks/renderTargetChunk.js
+++ b/src/core/display/chunks/renderTargetChunk.js
@@ -36,7 +36,7 @@ SceneJS_ChunkFactory.createChunkType({
             //  Enable blending for non-depth targets
             if (frameCtx.blendEnabled) {
                 gl.enable(gl.BLEND);
-                gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
+                gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
             }
         }
 
diff --git a/src/core/display/programSourceFactory.js b/src/core/display/programSourceFactory.js
index e0e9c679..a4f79e33 100644
--- a/src/core/display/programSourceFactory.js
+++ b/src/core/display/programSourceFactory.js
@@ -1304,6 +1304,10 @@ var SceneJS_ProgramSourceFactory = new (function () {
             add("fragColor.rgb *= mix(SCENEJS_uFragmentFresnelEdgeColor.rgb, SCENEJS_uFragmentFresnelCenterColor.rgb, fragmentFresnel);");
         }
 
+        if (!depthTargeting) {
+            add("fragColor.rgb *= fragColor.a;");
+        }
+
         add("gl_FragColor = fragColor;");
 
         add("}");